For a number of years, it has been known that fresh water containing various dissolved minerals such as calcium and magnesium (calcareous material) could be effectively treated to reduce mineral precipitation from the water, when it is heated, by passing the water through a strong magnetic field. It is believed that passing the fresh water containing mineral through the magnetic field beneficially affects the growth pattern or crystal structure of the mineral ions dissolved in the fresh water. Subsequently, when the water is heated (which reduces the solubility of the minerals in the water at certain pH levels), the ions precipitate into the body of the water as discrete suspended particles, rather than deposit scale on the surfaces contacting the water. The individually suspended particles tend not to plate or deposit as scale on the walls of the water conduit and hence pass through the conduit along with the water. The calcareous material, after water containing the calcareous material is treated with a magnetic conditioner, is soft in texture and does not adhere to heat exchange surfaces.
The magnetic water conditioning device has also been found useful for removing existing scale which has been previously deposited in the conduit prior to installation of the magnetic water conditioner.
Prior magnetic water treating devices known to the applicant are disclosed in the following patents:
U.S. Pat. No. 2,678,729--Spondig (May, 1954) PA0 U.S. Pat. No. 2,652,925--Vermeiren (September, 1953) PA0 U.S. Pat. No. 2,825,464--Mack (March, 1958) PA0 U.S. Pat. No. 2,939,830--Green et al. PA0 U.S. Pat. No. 2,951,581--Moriya (September, 1960) PA0 U.S. Pat. No. 3,170,871--Moriya (February, 1963) PA0 U.S. Pat. No. 3,345,594--Vermeiren PA0 U.S. Pat. No. 3,669,274--Happ et al. (June, 1972) PA0 U.S. Pat. No. 3,680,705--Happ et al. (August, 1972) PA0 U.S. Pat. No. 3,923,660--Kottmeier (December, 1975) PA0 U.S. Pat . No. 4,146,479--Brown (March, 1979) PA0 British Pat. No. 1,423,927--Sundt (February, 1976)
The magnetic water conditioning devices disclosed in these various references have several serious shortcomings and two major shortcomings. First, the permanent magnets utilized in the devices are not effectively insulated from the water passing through the devices and consequently solid material tends to deposit on the magnets, and the magnets tend to corrode over a period of time, thereby reducing their effectiveness.
Secondly, none of the magnetic devices disclosed has any inherent capability to deal with changing water flow rates or water pressures, or to vary the force of the magnetic field in relation to the flow-rate of water through the device, without disassembling of the device and manual internal adjustment.
This latter deficiency is particularly troublesome in new installations where the quantity of water used per day by the user or the rate of water flow is not accurately known. Consequently the unit that is installed may be either oversize or undersize. In such a case, the only remedy is to replace the unit with a unit of a different size, at substantial expense.
An adjustable magnetic water conditioner sold under the trade mark AQUA-DIAL 15 is available from BSAL Kingston-upon-Thames, Surrey, England. However, the adjustability feature in that device is located internally within the device and hence the device must be disassembled in order to make any necessary adjustments. Additionally, the device does not provide a built-in Venturi effect.